SCREENING AND CHEMICAL INFORMATICS CORE: Screening Informatics: The key deliverables of the MLPCN are public data of high quality, published to PubChem, and supported chemical probe development. This mission requires two essential components, an Operational Environment for data management and quality assurance, and a Knowledge Environment facilitating efficient chemical probe optimization. The TSRI Center has these comprehensively on a production scale and will make key tools available broadly to maximize the impact of the MLPCN effort. We will also act quickly to implement policies and procedures recommended by the MLPCN steering committee. During MLSCN pilot phase, the informatics environment (described in Facilities and Other Resources), which is a critical and unifying link between La Jolla and Florida, has successfully managed assays on our institutional library, which exceeds 600,000 individual compounds, as well as >35 assays against the MLSMR 60-200K screening set. A metric of our current capabilities was the deposition of 80 assays with distinct AID's into PubChem. Automated submission to PubChem occurred within 5 +/- 4 days (mean/SD) of the completion of scientific Quality Assurance within the TSRI Center. The MLPCN mission will be supported by 3 Specific Aims for the Informatics Core: Aim 1: Maintain operational informatics infrastructure for MLPCN production phase. Aim 2: Knowledge Environment: Unlocking the efficiencies in probe development. Aim 3: Building the MLPC Network.